1. Technical Field
The present invention relates to a light scanning device and an image forming device.
2. Related Art
As a device of displaying a desired image (e.g., a commercial advertisement such as a commercial) on a screen, for example, there has been known a device, which is configured so as to respectively scan a laser beam emitted from a light source in horizontal and vertical directions of the screen using two galvanometer mirrors (see, e.g., JP-A-2003-131151). Further, in the device described in the related art document described above, the drive timing of each of the galvanometer mirrors is controlled by the detection signal of the optical sensor fixed on the screen. Further, it is also possible to obtain the maximum deflection angle of the galvanometer mirrors based on the detection signal of the optical sensor.
However, in the device described in the related art document described above, since the optical sensor is fixed with respect to the screen in the case of changing the size of the image on the screen by changing the maximum deflection angle of the galvanometer mirror, the detection accuracy of the optical sensor is apt to degrade depending on the level (in particular the case of a large deflection angle) of the maximum deflection angle of the galvanometer mirrors. In the case in which, for example, the maximum deflection angle is 40 degrees, and the optical sensor is disposed at the position where the optical sensor reacts the maximum deflection angle with the highest sensitivity, if the maximum deflection angle is changed to 80 degrees, the resolution of the deflection angle which can be detected by the optical sensor is degraded. As described above, according to the device described in the related art document described above, there arises a problem that the difference is caused in the detection accuracy of the maximum deflection angle, and it is unachievable to accurately detect the fact that the galvanometer mirror rotates (swings) at the maximum deflection angle to thereby control the galvanometer mirror.